Flotation apparatus and process



W. L. ZIEGLER. PLoTAloN APPARATUS AND PROCESS.

I APPLICATION FILED APR-4| 1911 v '12324,139. i Patented Dec. 9,1919.

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IFLOTATION AIVPPARATUS AND PROCESS.

vSpecification of Letters Patent.

Patented Dec. 9, 119119.

Application filed April 4, 1917. Serial No. 159,760. i

To all whom t may concern.'

Be it knovvn that I, VILLIAML. ZIEGLER, a citizen of the Unit-ed States of America, and a resident of Sunset, Idaho, have invented a nevv and useful Improvement in Flotation Apparatus and Processes, vvhich invention is fully set forth in the following specification.

This invention relates to an apparatus and process for the separation of the commingled ingredients of ore material, and is especially adapted for the separation of valuable metalliferous compounds, such as sulfids, from the rock yor earthy gangue vvith vvhich they are originally intermixed. More particularly, this invention relates to apparatus of the type commonly designated as flotation, vvherein pulverized ore, mixed With Water and oily material, is agitated for the separation of the metalliferous particles by taking advantage of their knovvn preference for oily globules or b ubbles.

For the efficient separation of metalliferous particles from the gangue by the flotation process, it is necessary that such particles be brought into intimate engagement With the oily bubbles or globules. It has heretofore been proposed to effect such result by subjecting the pulp to agitation by paddle Wheels submerged in the pulp. Such submerged paddle Wheels, however, have necessitated a large expenditure of power, and have proved ineflicient in that they have been effective in aerating the pulp onl by occlusion of air or by drawing in air y a vortex formed by rapid rotation of the Wheel. The resulting ineiiicient 'separation of the metalliferous particles from .the

gangue has necessitated the use of apparatus comprising a number of units in which the pulp is successively agitated, and the cost of installation and maintenance of such apparatus has limited the number of units, Withl the result that there has been an incomplete separation of the metalliferous values from the gangue. To obviate this difficulty, it has also been suggestedl to run the paddle Wheels `only partly submer ved and to substitute drum agitators. VS ile possessing certain economic advantages, these substituted agitators have failed to accomplish the end sought. It has also been proposed to eiiect the agitation by the use of jets of compressed air. This type of agitation, hoW- ever, has tended to roduce a relatively small number of large bubbles with a resultore pulp and therefore requires a minimum Y expenditure 0f energy to drive the same.

A still further object of this invention is to provide a device of the type described with an improved agitator whereby the ore .pulp is thoroughly agitated Without the production of large bubbles and the metalliferous values are separated and carried by a thick creamy froth having a' low percentage of moisture. Other object-s relate to the provision of a device of the type characterized Which is simple in construction, inexpensive to manufacture, efficient in operation, and ,has a maximum capacity for the space occupied.

Stated broadly the invention comprises an agitating chamber, means for supplying said chamber With ore pulp, preferably delivering said pulp to said chamber vertically, an agitator Within said chamber and preferably closely fitting the same, and a settling chamber to Which the agitated pulp is delivered from the agitator. Said agitator, in its preferred construction, comprises a horizontal shaft supporting a series of plates inclined to the axis of said shaft and connected by interposing members which may have the function 0f vanes in assisting in the agitation of the pulp.

Means are also preferably provided for thoroughly aerating the pulp prior to its delivery to said a gitating chamber, such means being shown as a nozzle for introducing compressed air into the pulp as it rises through the conduit deliverin to said charnber. Means are 'also preferab v provided for the escape of air from the agitating chamber prior to the delivery of the agitated pulp by the agitator to the settling chamber.

The invention is capable of receiving a Va; riety of mechanical `expressions, one of which is shown on the accompanying drawing, but it is to be expressly understood that the drawing is for purposes of illustration only and is not to be construed as a defini-4 tion of the limits of the invention, reference through thereof, an agitating chamber 2. Within chamber 2 is an agitator 3shown as comprising a horizontal shaft l rotatable in suitable bearings 5 on the frame 1 and carrying a pulley 6, and a series of circular plates 8 mounted upon said shaft and slightly inclined with respect to the axis thereof. The plates 8 are maintained in parallel relationship by spacing collars 9 of any suitable material carried by Saidshaft and having their end faces inclined to said shaft at the same angle as said plates 8. To stiifen the plates 8 and maintain the same parallel, they may be connected, adjacent their peripheries, by interposed members 10 suitably secured thereto. Fory convenience of construction, said members 10 may be constituted by longitudinal strips extending through each of the plates of the series and lsuitably riveted or soldered thereto. Any suitable number of these members 10 may be employed, and they may be made desirably of such shape and width as to constitute vanes and assist in fthe agitation of the pulp delivered thereto. As shown, the members l() are uniformly spaced circumferentially of the plates 8 and positioned in planes tangential to a relatively small circle concentric with the axis of the agitator 3 (see Fig. 2). To prevent the ore pulp iiowing longitudinally of the agitator, the latter is preferably made to closely lit the interior of the agitating chamber, and to this end the latter, if not circular in cross-section, is provided with longitudinal blocks or strips 11 interiorly shaped to coliform with and closely envelop the periphery of said agitator.

Anysuitable means may be provided for supplying the agitating chamber with ore pulp'. As shown, a vertical conduit 12 commumcates at its upper end with said cham ber and is supplied with ore pulp by any suitable feed pipe 13 adjacent the lower end of said conduit; Means are also preferably provided within this conduit 12 to thoroughly aerate the pulp, andv to this end compressed air is introduced into the upwardly fiowlng pulp through any suitable nozzle 13,

preferably positioned adjacent the lower end of the conduit 12. The compressed air so introduced into the pulp also assists in elevating the same to the agitating chamber and constitutes in effect an air-lift.

From the agitator theV pulp is delivered to a settling chamber 14, preferably provided with an inwardly inclined side or bottom 15 to guide the heavy particles settling therein toward the tailings-discharge pipe 16. By preference, the agitated pulp is not thrown from the agitator onto the surfaceof the liquid in the sett-ling chamber but is delivered thereto through a downwardly directed conduit 17 which extends to an appreciable distance below the surface of the liquid in said chamber. Means are also preferably provided for the escape of air from the pulp prior to its delivery from the agitator `to the settling chamber, and to this end an upwardly directed conduit 19 is in communication with the -upper portion of the agitating chamber 2. For convenience 0f construction, conduits 17 and 19 may have a common wall as shown at 18.

Any suitable means may be provided for discharging the froth collected on the surface of the liquid in the settling chamber to any suitable launder (not shown), a paddle wheel 2O rotatable b v any suitable means being diagrammatically illustrated on .the drawing. l

In operation, the ore is ground and intermixed with water, and a suitable quantity of oil or similar, substance, to provide a pulp of the proper consistency. Said ore lpulp is fed in any suitable'way through pipe 13, as by gravity or pressure, into the lower end of the 4vertically directed conduit 12, in which it rises to the settling chamber 2. 1n said conduit 12, the pulp is thoroughly aerated by compressed air admitted through nozzle 13 which assists also in the delivery of the pulp to Said agitating chamber. The ore pulp is thrown from conduit 12 onto agitator 8, rotating in the direction of the arrow shown in Fig. 2, by which it is carried around and discharged into conduit 17. Owing to the inclination of the plates 8, and aided by the vanes constituted by the interposed members 10 when used, the ore pulp is slapped and beaten whereby large bubbles are broken up and the oil and air are intimately interlningled with the metalliferous particles. Much of the air is beaten out of the pulp during this operation and escapes through the conduit 19. Owing to the close t of the agitator within the agitating chamber, the pulp cannot flow longitudinally thereof but is carried around by the agitator and discharged into the conduit 17. The frothy pulp discharged into the conduit 17 flows downwardly into the settling chamber, and the tiny globules or bubbles of oilin cased air, with the metalliferous particles adhering thereto, rise to the surface of the liquid in the settling chamber and constitute a thick creamy froth having a relatively small proportion of moisture and air, and carrying a relatively large .proportion of metalliferous values. The heavier particles and the gangue sink to the bottom of the settling chamber 14 and are deected laterally by the inclined side 15 toward thetailings-discharge pipe 16. The Afroth accumulated on the surface of the liquid flows inta.

the launder provided, aided by the paddle Wheel when used.

Inasmuch as the agitator does not run immersedin the ore pulp, a relatively small f expenditure of power is sufficient to run the same,:and, owing to the efficient aeration and agitation produced by the apparatus, with the consequent formation of a relatively large number of small bubbles or globules intimately intermiXed with the particles of ore pulp, an efficient `separation of the metalliferous values Vfrom the gangue is obtained.

Some ores, however, are vof .such nature that a single `aeration and agitation of the same is insufficient to separate the metalliferous values therefrom. In such event,

the apparatus may be constructed in the form of a plurality of cells, each preceding cell'communicating with the vertical supply conduit `12Lof the succeeding unit and the last unit or .cell being provided with a tailsome of which `will readily suggest themselves to those skilled in the art. Furthermore, certain features thereof are capable of use to the accomplishment of 'an improved result Without the use of other features thereof. Reference is therefore to be hadg to the appended claims for a denition of the limits of this invention.

What is claimed is:

1. In flotation apparatus, the combination .of a vertical conduit, means for introducing at the base of said conduit ore pulp and a jet of airto produce an upwardly flowing column of frothed pulp, a chamber located at the top of said conduit for receiving said frothed pulp, froth beating means in said chamber adapted to beat said frothed pulp as led into the froth beating chamber, a froth separating tank and a conduit open to said chamber and having one end opening into the atmosphere for venting of air and thekopposite end delivering froth to said tan beater, an uprising conduit adapted to feed a body of commingled ore pulp and gas bubbles directly Ato said beater, said beater :adapted to beat the wholeof said pulp into a froth and deliver the same to said froth separator.

3. In a dotation process for treatment of -ore pulp which consists of a mixture of ore vin fine division, water and a frothing agent,

the steps consisting in injecting air into an vupwardly moving column of said pulp produce a body of frothat the top of said column, beating the froth in a confined space at the top of the column as it leaves said column toebreak up the larger air bubbles and produce a creamy froth while permit- .ting excess of air to escape, and then separatling the froth and gangue.

In testimony whereof I have signed lthis specification.

wrLLrAM L; ZIEGLER.

'2. In combination, a froth separator, a 

